Donor substrate and method of manufacturing display

ABSTRACT

The present invention provides a donor substrate used in forming a light emitting layer by forming a transfer layer containing light emission material, irradiating a radiation ray to the transfer layer while the transfer layer and a substrate to be transferred face each other, and sublimating or vaporizing the transfer layer so that the transfer layer is transferred to the substrate to be transferred. The donor substrate includes: a base; a photothermal conversion layer arranged on the base; and a heat interfering layer arranged between the base and the photothermal conversion layer, and including two or more layers with refraction index different from each other.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a donor substrate used in forming alight emitting layer in an organic light emitting device by transfermethod, and a method of manufacturing a display using such a donorsubstrate.

2. Description of the Related Art

In recent years, displays for the next generation have been activelydeveloped, and an organic light emitting display using an organic lightemitting device (organic EL (electroluminescence) device) in which afirst electrode, a plurality of organic layers including a lightemitting layer, and a second electrode are stacked in this order on adriving substrate has attracted attention. Since the organic lightemitting display is self-emitting, it has a large view angle. In theorganic light emitting display, since a backlight is unnecessary,electric power saving is expected. Moreover, responsiveness is high, andlow-profile of the display is possible. Therefore, it is highly desiredthat the organic light emitting display be applied to a large-screendisplay such as a television.

For the purpose of increasing size and improving productivity in such anorganic light emitting display, there has been considered a use ofmother glass which is further large in size. At that time, in a methodof forming a light emitting layer using a typical metal mask, lightemitting layers of R, G, and B are patterned by evaporating or applyinglight emission material, with a metal mask in between. In the metalmask, an aperture pattern is provided on a metal sheet. Thus, with theincrease in size of a substrate, it is necessary to increase size of themetal mask.

However, with the increase in size of the metal mask, deflection due toweight of the mask itself and complication of delivery becomeremarkable, and alignment is difficult. Thus, it is difficult tosufficiently increase an aperture ratio, and device characteristics aredeteriorated as a result.

As a patterning technique without using a metal mask, there is atransfer method in which a radiation ray such as a laser is used. In thetransfer method, a donor element provided with a transfer layercontaining light emission material as supporting material is formed, andthe donor element faces a substrate to be transferred for forming theorganic light emitting device. Then, the transfer layer is transferredto the substrate to be transferred by irradiating a radiation ray undera reduced-pressure environment. In addition to the laser, as theradiation ray, there is a case where light from a xenon flash lamp iscondensed by a lens and used (for example, refer to Japanese UnexaminedPatent Publication No. 1997-167684 (paragraphs 0017 and 0028)).

In a donor substrate of the related art, for example, a photothermalconversion layer of chrome (Cr) or the like is patterned to only adesired region (region desired to be transferred) in a base of glass ora film. In a transfer step, a transfer layer of organic material isformed on a donor substrate, and laser light is locally irradiatedcorresponding to the photothermal conversion layer. Thereby, only thedesired range in the transfer layer is transferred to a substrate to betransferred.

SUMMARY OF THE INVENTION

However, in the case of thermal transfer by using laser, when size ofthe substrate is increased, there is an issue that processing time isextended and cost of the display or the like is up. Thus, a xenon flashlamp, a halogen infrared lamp, and the like are considered promising asradiation sources replacing the laser, since a collective or traversableprocessing may be performed in a large area. However, a donor substratecapable of efficiently absorbing a radiation ray with a wide wavelengthsuch as a flash lamp and a halogen infrared lamp has not been developedin the related art, and large power loss occurs in the case of using adonor substrate of the related art.

Moreover, in the donor substrate of the relate art, a surface of thebase and the photothermal conversion layer are covered with a heatinsulating layer of SiO₂ or the like, and a pollution preventing layerof molybdenum (Mo) or the like is formed on the heat insulating layer.Thus, heat in a light absorbing layer is radially diffused in a plane ofthe pollution preventing layer, and organic material for the transferlayer is melted and slack of an outline occurs. Accordingly, not onlythe desired range in the transfer layer, but also an undesired range(region undesired to be transferred) is transferred. Therefore, transferaccuracy is reduced and color mixture to an immediately adjacent pixeloccurs, and these bring remarkable reduction in productivity.

In view of the foregoing, it is desirable to provide a donor substratecapable of efficiently absorbing a radiation ray with a wide wavelengthand a method of manufacturing a display using the donor substrate.

It is further desirable to provide a donor substrate capable oftransferring a desired range in a transfer layer with high accuracy anda method of manufacturing a display using the donor substrate.

According to an embodiment of the present invention, there is provided afirst donor substrate used in forming a light emitting layer by forminga transfer layer containing light emission material, irradiating aradiation ray to the transfer layer while the transfer layer and asubstrate to be transferred face each other, and sublimating orvaporizing the transfer layer so that the transfer layer is transferredto the substrate to be transferred. The donor substrate includes thefollowing components (A) to (C).

(A) a base;

(B) a photothermal conversion layer arranged on the base; and

(C) a heat interfering layer arranged between the base and thephotothermal conversion layer, and including two or more layers withrefraction index different from each other.

According to an embodiment of the present invention, there is provided asecond donor substrate used in forming a light emitting layer by forminga transfer layer containing light emission material, irradiating aradiation ray while the transfer layer and a substrate to be transferredface each other, and sublimating or vaporizing the transfer layer sothat the transfer layer is transferred to the substrate to betransferred. The donor substrate includes the following components (A)to (E).

(A) a base;

(B) a photothermal conversion layer arranged on the base, correspondingto a region where a light emitting layer on the substrate to betransferred is to be formed;

(C) a heat insulating layer formed on the photothermal conversion layerand the base;

(D) a convex structure arranged in a region between the photothermalconversion layers on the heat insulating layer; and

(E) a pollution preventing layer including a first portion formed on atop surface of the convex structure and a second portion formed on a topsurface of the heat insulating layer, the first portion and the secondportion being separated from each other.

A first method or a second method of manufacturing a display accordingto embodiments of the present invention in which an organic lightemitting device including a first electrode, an insulating layerincluding an aperture corresponding to a light emitting region of thefirst electrode, a plurality of organic layers including a lightemitting layer, and a second electrode in this order is formed on adriving substrate includes the steps of: forming the first electrode,the insulating layer, a part of the plurality of organic layers on thedriving substrate, thereby forming a substrate to be transferred;forming a transfer layer containing light emission material in a donorsubstrate, irradiating a radiation ray while the transfer layer and thesubstrate to be transferred face each other, and sublimating orvaporizing the transfer layer so that the transfer layer is transferredto the substrate to be transferred, thereby forming a light emittinglayer; and forming remains of the plurality of organic layers and thesecond electrode. As the donor substrate, the first or the second donorsubstrate according to the embodiments of the present invention is used.

In the first donor substrate according to the embodiment of the presentinvention, a heat interfering layer including two or more layers withrefraction index different from each other is arranged between the baseand the photothermal conversion layer. Thereby, reflectance of the heatinterfering layer is adjusted depending on a light emission band of theradiation ray, and absorption when the radiation ray irradiated to thedonor substrate is absorbed in the photothermal conversion layer andconverted into heat is improved.

In the second donor substrate according to the embodiment of the presentinvention, the pollution preventing layer includes a first portionformed on a top surface of the convex structure and a second portionformed on a top surface of the heat insulating layer, and the firstportion and the second portion are separated from each other. Thus, heatdiffusion through the pollution preventing layer is highly reduced.Thereby, a risk that an undesired range in the transfer layer istransferred is reduced, and a desired range is transferred with highaccuracy.

In the first donor substrate according to the embodiment of the presentinvention, a heat interfering layer including two or more layers withrefraction index different from each other is arranged between the baseand the photothermal conversion layer. Thereby, the absorption improvesin a wide wavelength range by adjusting refraction index (material) andthe thickness of the heat interfering layer.

In the second donor substrate according to the embodiment of the presentinvention, the pollution preventing layer includes a first portionformed on a top surface of the convex structure and a second portionformed on a top surface of the heat insulating layer, and the firstportion and the second portion are separated from each other. Thereby,the heat diffusion through the pollution preventing layer is highlyreduced, and the desired range in the transfer layer is transferred withhigh accuracy. Therefore, when manufacturing the organic light emittingdisplay by using the donor substrate, the light emitting layer is formedwith high precision without using a mask.

Other and further objects, features and advantages of the invention willappear more fully from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view illustrating the configuration of a display accordingto a first embodiment of the present invention.

FIG. 2 is a view illustrating an example of a pixel driving circuit inFIG. 1.

FIG. 3 is a cross-sectional view illustrating the configuration of adisplay region in FIG. 1.

FIGS. 4A to 4C are plan views illustrating the configuration of a firstelectrode and an insulating layer in FIG. 3.

FIG. 5 is a cross-sectional plan view illustrating the configuration ofa donor substrate used in a method of manufacturing the display in FIG.1.

FIGS. 6A and 6B are cross sectional views illustrating a method ofmanufacturing the donor substrate in process order.

FIGS. 7A and 7B are cross sectional views illustrating a method ofmanufacturing the display in FIG. 1 in process order.

FIG. 8 is a cross-sectional view for explaining operation of a rib inFIGS. 4A to 4C.

FIGS. 9A and 9B are cross-sectional views for explaining an example andan issue of a donor substrate of the related art.

FIG. 10 is a cross-sectional view illustrating a modification of thestep in FIG. 7B.

FIG. 11 is a cross-sectional view illustrating a modification of thedonor substrate in FIG. 5.

FIG. 12 is a cross-sectional view illustrating the method ofmanufacturing the display using the donor substrate in FIG. 11.

FIG. 13 is a cross-sectional view illustrating a modification of thestep in FIG. 12.

FIG. 14 is a cross-sectional view illustrating the configuration of adonor substrate according to a second embodiment of the presentinvention.

FIG. 15 is a cross-sectional view illustrating a donor substrateaccording to a third embodiment of the present invention.

FIG. 16 is a view illustrating an absorption spectrum in a heatinterfering layer.

FIG. 17 is a view illustrating the absorption spectrum in the heatinterfering layer.

FIG. 18 is a view illustrating the absorption spectrum in the heatinterfering layer.

FIG. 19 is a cross-sectional view illustrating a transfer step by usingthe donor substrate in FIG. 15.

FIG. 20 is a plan view illustrating an example of a method ofirradiating a radiation ray.

FIG. 21 is a plan view illustrating another example of the method ofirradiating the radiation ray.

FIG. 22 is a cross-sectional view illustrating a modification of thedonor substrate in FIG. 15.

FIGS. 23A and 23B are cross-sectional views for explaining theconfiguration and an issue of a donor substrate in Comparative example1.

FIG. 24 is a plan view illustrating the schematic configuration of amodule including the display in the first to third embodiments.

FIG. 25 is a perspective view illustrating appearance of Applicationexample 1 of the display in the first to third embodiments.

FIG. 26A is a perspective view illustrating appearance as seen from afront side of Application example 2, and FIG. 26B is a perspective viewillustrating appearance as seen from a rear side of Application example2.

FIG. 27 is a perspective view illustrating appearance of Applicationexample 3.

FIG. 28 is a perspective view illustrating appearance of Applicationexample 4.

FIG. 29A is a front view in an opened state of Application example 5,FIG. 29B is a side view in the opened state, FIG. 29C is a front view ina closed state, FIG. 29D is a left side view in the closed state, FIG.29E is a right side view in the closed state, FIG. 29F is a top view inthe closed state, and FIG. 29G is a bottom view in the closed state.

FIG. 30 is a cross-sectional view illustrating the configuration of adisplay region after formation of a blue-light emitting layer.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will be described indetail with reference to the accompanying drawings. The description willbe made in a following order.

1. First embodiment (example where laser light is used as a radiationray and a convex structure is provided in a donor substrate).

2. Modification 1 (example where transfer layers of different colors foreach region which is separated by the convex structure are provided).

3. Second embodiment (example where a heat interfering layer with asingle-layer structure is provided between a base and a photothermalconversion layer).

4. Third embodiment (example where a heat interfering layer has astacked structure by using radiation source with a wide wavelength).

First Embodiment Display

FIG. 1 illustrates the configuration of a display according to a firstembodiment of the present invention. The display is used as alow-profile organic light emitting color display or the like. In thedisplay, for example, a display region 110 in which a plurality of lightemitting devices 10R, 10G, and 10B which will be described later arearranged in matrix is formed on a driving substrate 11 of glass, and asignal line driving circuit 120 and a scanning line driving circuit 130as drivers for image display are formed in vicinity of the displayregion 110.

In the display region 110, a pixel driving circuit 140 is formed. FIG. 2illustrates an example of the pixel driving circuit 140. The pixeldriving circuit 140 is formed in a layer level below that of a firstelectrode 13 which will be described later. The pixel driving circuit140 is an active driving circuit including a driving transistor Tr1 anda writing transistor Tr2, a capacitor Cs (retention capacity) arrangedbetween the driving transistor Tr1 and the writing transistor Tr2, andthe organic light emitting device 10R (or 10G or 10B) connected inseries to the driving transistor Tr1 between a first power source line(Vcc) and a second power source line (GND). The driving transistor Tr1and the writing transistor Tr2 are configured with a typical thin filmtransistor (TFT). For example, the structure of the TFT is notspecifically limited, and may be an inverted staggered structure(so-called bottom-gate type) or a staggered structure (top-gate type).

In the pixel driving circuit 140, a plurality of signal lines 120A arearranged in a column direction, and a plurality of scanning lines 130Aare arranged in a row direction. An intersection between each signalline 120A and each scanning line 130A corresponds to either one(sub-pixel) of the organic light emitting devices 10R, 10G and 10B. Eachsignal line 120A is connected to the signal line driving circuit 120,and an image signal is supplied from the signal line driving circuit 120to a source electrode of the writing transistor Tr2 through the signalline 120A. Each scanning line 130A is connected to the scanning linedriving circuit 130, and a scanning signal is supplied in sequence fromthe scanning line driving circuit 130 to a gate electrode of the writingtransistor Tr2 through the scanning line 130A.

FIG. 3 illustrates an example of the cross-sectional configuration ofthe display region 110. In the display region 110, the organic lightemitting device 10R generating red light, the organic light emittingdevice 10G generating green light, and the organic light emitting device10B generating blue light are formed in this order in matrix as a whole.The organic light emitting devices 10R, 10G, and 10B have a rectangularflat shape, and are arranged in a longitudinal direction (columndirection) for each color. A combination of the organic light emittingdevices 10R, 10G, and 10B immediately adjacent to one another constituteone pixel. Pixel pitch is, for example, 300 μm.

In the organic light emitting devices 10R, 10G, and 10B, a firstelectrode 13 as an anode, an insulating layer 14, an organic layer 15including a red light emitting layer 15CR, a green light emitting layer15CG, or a blue light emitting layer 15CB which will be described later,and a second electrode 16 as a cathode are stacked in this order fromthe driving substrate 11 side with a driving transistor (not illustratedin the figure) and a planarized insulating film (not illustrated in thefigure) in the above-described pixel driving circuit 140 in between.

Such organic light emitting devices 10R, 10G, and 10B are covered with aprotective film 17 of silicon nitride (SiNx) or the like. Moreover, theorganic light emitting devices 10R, 10G, and 10B are sealed by adheringa sealing substrate 30 of glass or the like over the whole surface ofthe protective layer 17 with an adhering layer 20 in between.

The first electrode 13 is made of, for example, ITO (indium-tincomposite oxide) or IZO (indium-zinc composite oxide). The firstelectrode 13 may be configured with a reflecting electrode. In thatcase, the first electrode 13 has, for example, a thickness of 100 nm ormore and 1000 nm or less, and it is preferable that the first electrode13 have reflectance as high as possible to improve light emittingefficiency. As material for the first electrode 13, for example, thereis simple substance of a metal element such as chrome (Cr), gold (Au),platinum (Pt), nickel (Ni), copper (Cu), tungsten (W), or silver (Ag),or alloy of those.

The insulating layer 14 assures insulating properties between the firstelectrode 13 and the second electrode 16, and properly makes a lightemitting region into a desirable shape. The insulating layer 14 has, forexample, a thickness of approximately 1 μm, and is made ofphotosensitive resin such as silicon oxide or polyimide. In theinsulating layer 14, an aperture is provided corresponding to a lightemitting region 13A in the first electrode 13. The insulating layer 14also serves as a convex structure on the driving substrate 11 sidecorresponding to a convex structure 44 in a donor substrate 40 whichwill be described later. The organic layer 15 and the second electrode16 may be arranged on not only the light emitting region 13A but alsothe insulating layer 14 continuously. However, light emission isgenerated only in the aperture of the insulating layer 14.

FIGS. 4A to 4C illustrate an example of the plan configuration of thefirst electrode 13 and the insulating layer 14. The insulating layer 14is provided in, for example, a lattice pattern. On the insulating layer14, a rib 14A is arranged in a position away from the light emittingregion 13A in the first electrode 13 (for example, an intersection ofthe lattice in the insulating layer 14). The rib 14A avoids that theconvex structure 44 in the donor substrate 40 and the insulating layer14 are in contact with each other in a transfer step which will bedescribed later. Therefore, a height H of the rib 14A is preferablyhigher than that of the convex structure 44, and may be, for example,approximately 5 μm. The rib 14A is made of, for example, the samematerial as the insulating film 14. On the driving substrate 11, analignment mark M is provided for a position alignment with the donorsubstrate 40 in the transfer step which will be described later.

The organic layer 15 illustrated in FIG. 3 has a configuration in whicha hole injecting layer and a hole transporting layer 15AB, the red lightemitting layer 15CR, the green light emitting layer 15CG, or the bluelight emitting layer 15CB, and an electron transporting layer and anelectron injecting layer 15DE are stacked in this order from the firstelectrode 13 side. Among them, the layers except the red light emittinglayer 15CR, the green light emitting layer 15CG, and the green lightemitting layer 15CB may be provided if necessary. The configuration ofthe organic layer 15 may depend on a color of light emitted from theorganic light emitting devices 10R, 10G, and 10B. The hole injectinglayer increases hole injection efficiency, and is a buffer layerpreventing leakage. The hole transporting layer increases holetransportation efficiency to the red light emitting layer 15CR, thegreen light emitting layer 15CG, or the blue light emitting layer 15CB.Recombination of an electron and a hole occurs by applying electricfield, and the red light emitting layer 15CR, the green light emittinglayer 15CG, or the blue light emitting layer 15CB generates light. Theelectron transporting layer increases electron transportation efficiencyto the red light emitting layer 15CR, the green light emitting layer15CG, or the blue light emitting layer 15CB. The electron injectinglayer has, for example, a thickness of approximately 0.3 nm, and is madeof LiF, Li₂O, or the like. In FIG. 3, the hole injecting layer and thehole transporting layer are illustrated as one layer (the hole injectinglayer and the hole transporting layer 15AB), and the electrontransporting layer and the electron injecting layer are illustrated asone layer (the electron transporting layer and the electron injectinglayer 15DE).

The hole injecting layer in the organic light emitting device 10R has,for example, a thickness of 5 nm or more and 300 nm or less, and is madeof 4,4′,4″-tris(3-methyl phenyl phenylamino)triphenylamine (m-MTDATA) or4,4′,4″-tris(2-naphthyl phenyl amino)triphenylamine (2-TNATA). The holetransporting layer in the organic light emitting device 10R has, forexample, a thickness of 5 nm or more and 300 nm or less, and is made ofbis[(N-naphthyl)-N-phenyl]benzidine (α-NPD). The red light emittinglayer 15CR in the organic light emitting device 10R has, for example, athickness of 10 nm or more and 100 nm or less, and is configured bymixing 2,6-bis[4′-methoxydiphenylamino)styryl]-1,5-dicyanonaphthalene(BSN) as 30 weight % into 9,10-di-(2-naphthyl)anthracene (ADN). Theelectron transporting layer in the organic light emitting device 10Rhas, for example, a thickness of 5 nm or more and 300 nm or less, and ismade of 8-hydroxyquinoline aluminum (Alq₃).

The hole injecting layer in the organic light emitting device 10G has,for example, a thickness of 5 nm or more and 300 nm or less, and is madeof m-MTDATA or 2-TNATA. The hole transporting layer in the organic lightemitting device 10G has, for example, a thickness of 5 nm or more and300 nm or less, and is made of α-NPD. The green light emitting layer15CG in the organic light emitting device 10G has, for example, athickness of 10 nm or more and 100 nm or less, and is configured bymixing coumarin 6 as 5 volume % into ADN. The electron transportinglayer in the organic light emitting device 10G has, for example, athickness of 5 nm or more and 300 nm or less, and is made of Alq₃.

The hole injecting layer in the organic light emitting device 10B has,for example, a thickness of 5 nm or more and 300 nm or less, and is madeof m-MTDATA or 2-TNATA. The hole transporting layer in the organic lightemitting device 10B has, for example, a thickness of 5 nm or more and300 nm or less, and is made of α-NPD. The blue light emitting layer 15CBin the organic light emitting device 10B has, for example, a thicknessof 10 nm or more and 100 nm or less, and is configured by mixing4,4′-bis[2-{4-(N,N-diphenylamino)phenyl}vinyl]biphenyl (DPAVBi) as 2.5weight % into ADN. The electron transporting layer in the organic lightemitting device 10B has, for example, a thickness of 5 nm or more and300 nm or less, and is made of Alq₃.

The second electrode 16 illustrated in FIG. 3 has, for example, athickness of 5 nm or more and 50 nm or less, and is made of simplesubstance of a metal element such as aluminum (Al), magnesium (Mg),calcium (Ca), or natrium (Na), or alloy of those. Among them, alloy(MgAg alloy) of magnesium and silver, or alloy (AlLi alloy) of aluminum(Al) and lithium (Li) is preferable.

The protective film 17 illustrated in FIG. 3 prevents that moisture orthe like seeps into the organic layer 15. The protective film 17 is madeof material having low water permeability and low water absorbability,and has a sufficient thickness. Moreover, the protective film 17 hashigh transmittance to light generated in the light emitting layer 15C,and is made of, for example, material having transmittance of 80% ormore. Such a protective film 17 has, for example, a thickness fromapproximately 2 μm to 3 μm, and is made of inorganic amorphousinsulating material. Specifically, amorphous silicon (α-Si), amorphoussilicon carbide (α-SiC), amorphous silicon nitride (α-Si_(1-x)N_(x)),and amorphous carbon (α-C) are preferable. Since the inorganic amorphousinsulating material does not constitute a grain and has low waterpermeability, the protective film 17 is favorably formed with suchmaterial. The protective film 17 may be made of transparent conductivematerial such as ITO.

The adhering layer 20 illustrated in FIG. 3 is made of, for example,heat curable resin or ultraviolet curable resin.

The sealing substrate 30 illustrated in FIG. 3 is placed on the secondelectrode 16 side of the organic light emitting devices 110R, 10G, and10B. The sealing substrate 30 seals the organic light emitting devices10R, 10G, and 10B in cooperation with the adhering layer 20, and is madeof material such as transparent glass which has high transmittance tolight generated in the organic light emitting devices 10R, 10G, and 10B.In the sealing substrate 30, for example, a color filter (notillustrated in the figure) is provided. The color filter takes out lightgenerated in the organic light emitting devices 10R, 10G, and 10B, andabsorbs natural light reflected by the organic light emitting devices10R, 10G, and 10B, and by wiring between the organic light emittingdevices 10R, 10G, and 10B to improve contrast.

Donor Substrate

Next, the donor substrate used in the method of manufacturing thedisplay will be described.

FIG. 5 illustrates the configuration of the donor substrate. The donorsubstrate 40 is used in a step of forming the red light emitting layer15CR, the green light emitting layer 15CG, or the blue light emittinglayer 15CB by transfer method. In the donor substrate 40, a photothermalconversion layer 42, a heat insulating layer 43, the convex structure44, and a pollution preventing layer 45 are stacked in this order on abase 41.

As will be described later, the base 41 is used when forming thetransfer layer containing light emission material constituting the redlight emitting layer 15CR, the green light emitting layer 15CG, or theblue light emitting layer 15CB. The base 41 is made of material havingfirmness with which position alignment with a substrate to betransferred which will be described later is possible, and having hightransmittance to laser light. For example, the base 41 is made of glassor a film.

The photothermal conversion layer 42 absorbs laser light and convertsthe laser light into heat, and is made of metal material having highabsorption such as molybdenum (Mo), chrome (Cr), titanium (Ti), or tin(Sn), or alloy containing those. The photothermal conversion layer 42is, for example, formed in a stripe shape with a width of 100 μmcorresponding to a region (light emitting region 13A) where the redlight emitting layer 15CR, the green light emitting layer 15CG, or theblue light emitting layer 15CB on the driving substrate 11 is desired tobe formed.

The heat insulating layer 43 suppresses heat diffusion from thephotothermal conversion layer 42, and is formed over the whole surfaceof the photothermal conversion layer 42 and the base 41. The heatinsulating layer 43 has, for example, a thickness of approximately 300nm, and is made of SiO₂, SiN, SiON, or Al₂O₃.

The convex structure 44 is formed in a stripe shape in a region betweenthe photothermal conversion layers 42 on the heat insulating layer 43,and is made of, for example, polyimide or acrylic resin.

By reflecting laser light irradiated to a region except the desiredrange in the transfer layer, the pollution preventing layer 45 protectsthe organic layer 15 and the pixel driving circuit 140 which are alreadyformed on the substrate to be transferred. It is preferable that thepollution preventing layer 45 have, for example, reflectance of 85% ormore in a wavelength region from 450 nm to 1500 nm. This is because whenthe reflectance of the pollution preventing layer 45 is low, there is arisk that the pollution preventing layer 45 absorbs light and takesheat. As material for the pollution preventing layer 45, for example,there is molybdenum (Mo), chrome (Cr), titanium (Ti), or tin (Sn), oralloy containing those.

The pollution preventing layer 45 includes a first portion 45A formed onthe top surface of the convex structure 44, and a second portion 45Bformed on the top surface of the heating insulating layer 43. The firstportion 45A and the second portion 45B are separated from each other.Thereby, in the donor substrate 40, the desired range in the transferlayer is transferred with high accuracy.

That is, by separating the first portion 45A and the second portion 45Bin the pollution preventing layer 45, the convex structure 44 serves asa heat diffusion preventing section reducing the heat diffusion throughthe pollution preventing layer 45. Thus, the convex structure 44preferably has a cross section of an inverse tapered shape with a bottomwidth W2 smaller than a top width W1. This is because, at the time ofdepositing the pollution preventing layer 45, it is possible to properlyseparate the first portion 45A and the second portion 45B without alithography step. Moreover, in the case where the transfer layer isformed by ink-jet method, it is possible to suppress leakage of a liquiddrop to outside the convex structure 44. Specifically, a tilt angle ofbetween the side face of the convex structure 44 and the flat surface ofthe base 41 is preferably 75 degrees or more and 140 degrees or less.

The convex structure 44 preferably has a height of 0.3 μm or more and 10μm or less. When the distance between the photothermal conversion layer42 and the first portion 45A in the pollution preventing layer 45 is setlong, the heat diffusion through the heat insulating layer 43 and theconvex structure 44 itself is reduced.

Moreover, the pollution preventing layer 45 preferably has a thicknessof 25 nm or more and 500 nm ore less. When the thickness is less than 25nm, laser light transmits the pollution preventing layer 45, and thesufficient efficiency is not obtained. When the thickness is more than500 nm, it is difficult to properly separate the first portion 45A andthe second portion 45B at the time of depositing the pollutionpreventing layer 45.

The donor substrate 40 may be manufactured in a manner described below.

As illustrated in FIG. 6A, the photothermal conversion layer 42 of theabove-described material is formed on the base 41 of the above-describedmaterial by, for example, sputtering method, and is shaped into apredetermined shape by photolithography and etching. Next, asillustrated in FIG. 6B, the heat insulating layer 43 of theabove-described material is formed by, for example, CVD (chemical vapordeposition) method.

Next, as illustrated FIG. 6B, photosensitive resin is applied over thewhole surface of the base 41, and is shaped into a predetermined shapeby, for example, photolithography method and burned. Thereby the convexstructure 44 is formed. At that time, the convex structure 44 has, forexample, a height of 3 μm, and the cross section of an inverse taperedshape.

After that, the pollution preventing layer 45 of the above-describedmaterial is formed in a thickness of, for example, 150 nm by sputtering.At this time, the pollution preventing layer 45 discontinues at the sideface of the convex structure 44, and is separated to the first portion45A formed on the top surface of the convex structure 44 and the secondportion 45B formed on the top surface of the heat insulating layer 43.Therefore, a patterning step such as photolithography is unnecessary. Inthis manner, the donor substrate 40 illustrated in FIG. 5 is formed.

Method of Manufacturing Display

The display may be manufactured, for example, in a manner describedbelow.

The first electrode 13, the insulating layer 14, and the hole injectinglayer and the hole transporting layer 15AB are formed on the drivingsubstrate 11, and thereby the substrate to be transferred 11A is formed.

That is, the driving substrate 11 of the above-described material isprepared, and the pixel driving circuit 140 is formed on the drivingsubstrate 11. After that, a planarized insulating film (not illustratedin the figure) is formed by applying photosensitive resin over the wholesurface of the driving substrate 11. The planarized insulating film ispatterned to a predetermined shape by exposure and development, and aconnecting hole (not illustrated in the figure) between the drivingtransistor Tr1 and the first electrode 13 is formed and burned.

Next, the first electrode 13 of the above-described material is formedby, for example, sputtering method, and is shaped into a predeterminedshape by, for example, dry etching. In a predetermined position on thedriving substrate 11, an alignment mark used for the position alignmentwith a donor substrate in the transfer step which will be describedlater may be formed.

Next, the insulating layer 14 is formed over the whole surface of thedriving substrate 11, and the aperture is provided corresponding to thelight emitting region 13A in the first electrode 13 by, for example,photolithography method.

On the insulating layer 14, the rib 14A of the above-described materialwith the above-described height is provided in the position away fromthe light emitting region 13A in the first electrode 13 (for example, anintersection of the lattice in the insulating layer 14).

After that, the hole injecting layer and the hole transporting layer15AB of the above-described material with the above-described thicknessis deposited in order by, for example, evaporation method using an areamask. Thereby, the substrate to be transferred 11A is formed.

After forming the substrate to be transferred 11A, a plurality of theabove-described donor substrates 40 are prepared, and either one of ared, green, or blue transfer layer 50 is formed in each donor substrate40 by, for example, vacuum evaporation method as illustrated in FIG. 7A.

Next, the red light emitting layer 15CR, the green light emitting layer15CG, or the blue light emitting layer 15CB is formed by transfer methodusing the donor substrate 40. That is, as illustrated in FIG. 7B, forexample, when forming the red light emitting layer 15CR, the transferlayer 50 in the donor substrate 40 faces the substrate to be transferred11A. At that time, since the rib 14A (refer to FIGS. 4A to 4C) isprovided on the insulating film 14 in the substrate to be transferred11A, a space G is formed between the convex structure 44 in the donorsubstrate 40 and the insulating layer 14. Thus, as illustrated in FIG.8, the convex structure 44 and the insulating layer 14 are not incontact with each other. Therefore, deterioration of image qualitycaused by a light emission line or the like is avoided while suppressinggeneration of steps in the deposited organic layer 15 due to the contactbetween the convex structure 44 and the insulating layer 14.

Next, as illustrated in FIG. 7B, a laser light LB is irradiated from therear surface side of the donor substrate 40, and the transfer layer 50is sublimated or vaporized and thus transferred to the substrate to betransferred 11A. Thereby, the red light emitting layer 15CR is formed.Here, the pollution preventing layer 45 includes the first portion 45Aformed on the top surface of the convex structure 44 and the secondportion 45B formed on the top surface of the heat insulating layer 43,and the first portion 45A and the second portion 45B are separated fromeach other. Thereby, the heat diffusion through the pollution preventinglayer 45 is highly reduced. Therefore, a risk that the undesired rangein the transfer layer 50 is transferred is reduced, and the desiredrange is transferred with high accuracy.

On the other hand, as illustrated in FIG. 9A, in a donor substrate ofthe related art, since a pollution preventing layer 845 is continuouslyformed over the whole surface of a heat insulating layer 844, heat froma photoelectric conversion layer 842 is radially diffused in a plane ofthe pollution preventing layer 845 as indicated with arrow A1 in FIG.9B. Thus, organic material for a transfer layer 850 is melted and slackof the outline occurs. Accordingly, not only a desired range 852 in thetransfer layer 850, but also an undesired range (region undesired to betransferred) 851 is transferred. Therefore, transfer accuracy is reducedand color mixture to an immediately adjacent pixel occurs, and thesebring remarkable reduction in productivity. In FIGS. 9A and 9B,reference numerals in the 800s are used to indicate substantiallyidentical components to those in FIGS. 5, 7A, and 7B.

As illustrated in FIG. 10, the laser light LB may be irradiated to thewhole rear surface side of the donor substrate 40. In this case, in aregion where the photothermal conversion layer 42 is not formed, thelaser light LB is reflected by the pollution preventing layer 45 asindicated with arrow A4, and the undesired range 51 in the transferlayer 50 is not transferred. On the other hand, in the region where thephotothermal conversion layer 42 is formed, the laser light LB isabsorbed in the photothermal conversion layer 42, and only the desiredrange 52 in the transfer layer 50 is transferred to the substrate to betransferred 11A.

After that, similarly to the red light emitting layer 15CR, the greenlight emitting layer 15CG or the blue light emitting layer 15CB isformed.

After forming the red light emitting layer 15CR, the green lightemitting layer 15CG, or the blue light emitting layer 15CB, the donorsubstrate 40 and the substrate to be transferred 11A are separated. Inthe substrate to be transferred 11A, the electron transporting layer andthe electron injecting layer 15DE, and the second electrode 16 areformed by, for example, evaporation method. In this manner, the organiclight emitting devices 10R, 10G, and 10B are formed. After remains ofthe transfer layer 50 are washed and removed and the pollutionpreventing layer 45 is stripped by dry process or wet process, the donorsubstrate 40 which has been already used is repeatedly usable.

After forming the organic light emitting devices 10R, 10G, and 10B, theprotective film 17 of the above-described material is formed on theorganic light emitting devices 10R, 10G, and 10B. As a method of formingthe protective film 17, for example, deposition method such asevaporation method or CVD method in which energy of a depositionparticle is small to an extent that there is no influence to a base ispreferable. The protective film 17 is preferably formed continuouslyafter formation of the second electrode 16 without subjecting the secondelectrode 16 to atmosphere. Thereby, it is suppressed that the organiclayer 15 is deteriorated by being subjected to moisture or oxygen inatmosphere. Moreover, to avoid the reduction in luminance caused by thedeterioration of the organic layer 15, it is preferable that thedeposition temperature of the protective film 17 be set at normaltemperature and the deposition be performed under conditions wherestress of the film is the minimum to avoid peeling of the protectivefilm 17.

After that, the adhering layer 20 is formed on the protective film 17,and the protective film 17 and the sealing substrate 30 in which a colorfilter is provided are adhered with the adhering layer 20 in between. Atthat time, it is preferable that the face where the color filter in thesealing substrate 30 is formed be placed on the organic light emittingdevices 10R, 10G, and 10B side. Thereby, the display in FIG. 1 iscompleted.

In the display obtained in this manner, the scanning signal is suppliedfrom the scanning line driving circuit 130 to each pixel through a gateelectrode in the writing transistor Tr2, and an image signal from thesignal line driving circuit 120 is retained in a retention capacity Csthrough the writing transistor Tr2. That is, the driving transistor Tr1is on-off controlled depending on the signal retained in the retentioncapacity Cs. Thereby, a driving current Id is injected to each of theorganic light emitting devices 10R, 10G, and 10B, and light emission isgenerated by recombination of a hole and an electron. This lighttransmits the second electrode 16, the color filter, and the sealingsubstrate 30, and is taken out.

In this manner, in the first embodiment, the pollution preventing layer45 includes the first portion 45A formed on the top surface of theconvex structure 44, and the second portion 45B formed on the topsurface of the heat insulating layer 43, and the first portion 45A andthe second portion 45B are separated from each other. Thereby, the heatdiffusion through the pollution preventing layer 45 is highly reduced,and the desired range in the transfer layer 50 is transferred with highaccuracy. Therefore, when the organic light emitting display ismanufactured by using the donor substrate 40, the red light emittinglayer 15CR, the green light emitting layer 15CG, or the blue lightemitting layer 15CB is formed with high precision without using a mask.

Modification 1

FIG. 11 illustrates the configuration of a donor substrate 40A accordingto Modification 1 of the present invention. In the donor substrate 40Ain Modification 1, a photothermal conversion layer 42 is provided foreach region separated with a convex structure 44. Thereby, it ispossible that a transfer layer containing light emission material ofdifferent colors for each region is formed, and the number of transfersis reduced. Except the above, the configuration is the same as the firstembodiment.

The donor substrate 40A in Modification 1 may be manufactured in thesame manner as in the first embodiment except that the photothermalconversion layer 42 is provided for each region separated with theconvex structure 44.

Next, a method of manufacturing a display using the donor substrate 40Aof Modification 1 will be described.

Similarly to the first embodiment, a first electrode 13, an insulatinglayer 14, and a hole injecting layer and a hole transporting layer 15ABare formed on a driving substrate 11, and thereby a substrate to betransferred 11A is formed.

Next, as illustrated in FIG. 12, a red transfer layer 50R, a greentransfer layer 50G, and a blue transfer layer 50B containing lightemission material of different colors for each region separated by theconvex structures 44 are formed by, for example, ink-jet method.

Next, as illustrated in FIG. 12, a red light emitting layer 15CR, agreen light emitting layer 15CG, and a blue light emitting layer 15CBare formed in the substrate to be transferred 11A with a one-timetransfer by irradiating a laser light LB. Therefore, use efficiency ofthe light emission material improves, and running cost is reduced.Moreover, the number of transfers is reduced, and the cost for amanufacture device is reduced and manufacturing capability improves.

As illustrated in FIG. 13, the laser light LB may be irradiated to thewhole rear surface of the donor substrate 40A.

After forming the red light emitting layer 15CR, the green lightemitting layer 15CG, and the blue light emitting layer 15CB, the donorsubstrate 40A and the substrate to be transferred 11A are separated.Similarly to the first embodiment, an electron transporting layer and anelectron injecting layer 15DE, and a second electrode 16 are formed inthe substrate to be transferred 11A by, for example, evaporation method.In this manner, organic light emitting devices 10R, 10G, and 10B areformed.

Similarly to the first embodiment, after forming the organic lightemitting devices 10R, 10G, and 10B, a protective film 17 of theabove-described material is formed on the organic light emitting devices10R, 10G, and 10B. After that, an adhering layer 20 is formed on theprotective film 17, and a sealing substrate 30 in which a color filteris formed and the protective film 17 are adhered with the adhering layer20 in between. Thereby, the display illustrated in FIG. 1 is completed.

Second Embodiment

FIG. 14 illustrates the configuration of a donor substrate 40B accordingto a second embodiment of the present invention. The donor substrate 40Bhas the same configuration as the donor substrate 40 in the firstembodiment except that a heat interfering layer 46 is provided between abase 41 and a photothermal conversion layer 42. Therefore, samereference numerals are used to indicate substantially identicalcomponents, and the descriptions are omitted.

The base 41, the photothermal conversion layer 42, a heat insulatinglayer 43, a convex structure 44, and a pollution preventing layer 45 aremanufactured in the same manner as the first embodiment.

The heat insulating layer 46 increases absorption of a laser light LB inthe photothermal conversion layer 42. The heat insulating layer 46 has,for example, a thickness of 15 nm or more and 80 nm or less, and is madeof a-Si. The photothermal conversion layer 42 and the heat interferinglayer 46 are arranged corresponding to a region (light emitting region13A) where a red light emitting layer 15CR, a green light emitting layer15CG, and a blue light emitting layer 15CB on a substrate to betransferred 11A are to be formed.

The donor substrate 40B may be manufactured in the same manner as thefirst embodiment except that the heat interfering layer 46 and thephotothermal conversion layer 42 having the above-described thicknessand made of the above-described material are continuously formed on thebase 41, and then the heat interfering layer 46 and the photothermalconversion layer 42 are shaped into desirable shapes.

Similarly to the first embodiment, the donor substrate 40B may be usedin the method of manufacturing a display. At that time, since the donorsubstrate 40B is provided with the heat interfering layer 46 between thebase 41 and the photothermal conversion layer 42, the absorption of thelaser light LB in the photothermal conversion layer 42 is increased andloss is suppressed in a transfer step illustrated in FIG. 7B. Moreover,it is possible that the laser light LB with low power is used.

In this manner, in the second embodiment, since the heat interferinglayer 46 is provided between the base 41 and the photothermal conversionlayer 42, the absorption of the laser light LB in the photothermalconversion layer 42 is increased and the loss is suppressed, and thelaser light LB with the low power is usable.

Third Embodiment

FIG. 15 illustrates the configuration of a donor substrate 40C accordingto a third embodiment of the present invention. The donor substrate 40Chas the same configuration as in the first embodiment and the secondembodiment except that the donor substrate 40C has a stacked structurein which a heat interfering layer 46 includes two or more layers havingrefraction index different from each other, and a convex structure 44 isnot provided. Therefore, same reference numerals are used to indicatesubstantially identical components.

A base 41, a photothermal conversion layer 42, and a heat insulatinglayer 43 are manufactured in the same manner as the first embodiment andthe second embodiment.

As described above, the heat interfering layer 46 includes two or morelayers having refraction index different from each other. Specifically,the heat interfering layer 46 includes, for example, a first interferinglayer 46A of SiO₂, SiN, SiON, or Al₂O₃ with a thickness of 50 nm or moreand 200 nm or less, and a second interfering layer 46B of a-Si with athickness of 15 nm or more and 80 nm or less, in order from the base 41side. Thereby, in the donor substrate 40C, a radiation ray of a xenon orkrypton flash lamp, a beam halogen lamp, or the like having a widewavelength is efficiently absorbed.

The refraction index and the thickness of the two or more layers (forexample, the first interfering layer 46A and the second interferinglayer 46B) in the heat interfering layers 46 are adjusted so thatreflectance in a continuous wavelength region of 100 nm or more in alight emission band of the radiation ray is 0.1 or less. FIG. 16illustrates a comparison between an absorption spectrum of the casewhere the heat interfering layer 46 includes the first interfering layer46A of SiO₂ with a thickness of 100 nm and the second interfering layer46B of a-Si with a thickness of 15 nm, and an absorption spectrum of thecase where the heat interfering layer 46 does not include the firstinterfering layer 46A (case of a single-layer structure of the secondinterfering layer 46B). The reflectance is calculated by a reflectancecalculation method in a typical optical multilayer thin film (forexample, refer to Principles of Optics, Max Born and Emil Wolf, 1974(Pergamon press) or the like). From FIG. 16, it is understood that theabsorption is high in the wide-range wavelength region in the case wherethe heat interfering layer 46 has the stacked structure of the firstinterfering layer 46A and the second interfering layer 46B in comparisonwith the case where the first interfering layer 46A is not provided.

FIG. 17 illustrates the absorption spectrum in the case where the secondinterfering layer 46B has a thickness of 15 nm or 35 nm. FIG. 18illustrates the absorption spectrum in the case where the firstinterfering layer 46A has a thickness of 200 nm or 100 nm. From FIGS. 16to 18, it is understood that the absorption spectrum changes when thethickness of the first interfering layer 46A or the second interferinglayer 46B is changed.

In this manner, it is possible that the configuration of the heatinterfering layer 46 is optimized so that the maximum absorption isobtained in accordance with the light emission spectrum of the radiationray to be used. For example, a radiation ray of a xenon lamp, a xenonflash lamp, or the like mostly has a light emission band fromapproximately 400 nm to 1000 nm. Thus, from FIG. 17, it is understoodthat the transmittance in the continuous wavelength region of 100 nm ormore in the above-described light emission band is 0.1 or less when theheat interfering layer 46 has the stacked structure with the firstinterfering layer 46A of SiO₂ having a thickness of 100 nm and thesecond interfering layer 46B of a-Si having a thickness of 15 nm. Inthis case, effects similar to those in FIG. 17 are obtained when thefirst interfering layer 46A has a thickness of 50 nm or more and 100 nmor less and the second interfering layer 46B has a thickness of 15 nm ormore and 22 nm or less.

For example, infrared radiation heat of a halogen lamp or the likemostly has a light emission peak from approximately 900 nm to 1600 nmdepending on color temperature. Therefore, from FIG. 18, it isunderstood that the transmittance in the continuous wavelength region of100 nm or more in the above-described light emission band is 0.1 or lesswhen the heat interfering layer 46 has the stacked structure with thefirst interfering layer 46A of SiO₂ having a thickness of 200 nm and thesecond interfering layer 46B of a-Si having a thickness of 35 nm. Inthis case, effects similar to those in FIG. 18 are obtained when thefirst interfering layer 46A has a thickness of 150 nm or more and 250 nmor less, and the second interfering layer 46B has a thickness of 35 nmor more and 80 nm or less.

By the stacked structure of the heat interfering layer 46, it isunnecessary to provide the convex structure 44 in the donor substrate40C, and a pollution preventing layer 45 is continuously formed on thesurface of the heat insulating layer 43. Therefore, the configurationand the method of manufacturing the donor substrate 40C are simplified.

The donor substrate 40C is manufactured in the same manner as the firstembodiment except that, after continuously forming the first interferinglayer 46A, the second interfering layer 46B, and the photothermalconversion layer 42 of the above-described material with theabove-described thickness on the base 41, the first interfering layer46A, the second interfering layer 46B, and the photothermal conversionlayer 42 are shaped into predetermined shapes.

The donor substrate 40C may, for example, be used in the method ofmanufacturing a display as described below.

Similarly to the first embodiment, a first electrode 13, an insulatinglayer 14, and a hole injecting layer and a hole transporting layer 15ABare formed on a driving substrate 11, and thereby a substrate to betransferred 11A is formed.

Next, a plurality of the donor substrates 40C are prepared, and eitherone of a red, green, or blue transfer layer 50 is formed in each donorsubstrate 40C by, for example, vacuum evaporation method.

Next, a red light emitting layer 15CR, a green light emitting layer15CG, or a blue light emitting layer 15CB is formed by transfer methodusing the donor substrate 40C. That is, as illustrated in FIG. 19, forexample, when forming the red light emitting layer 15CR, the transferlayer 50 in the donor substrate 40C faces the substrate to betransferred 11A. At that time, similarly to the first embodiment, sincea rib 14A (refer to FIGS. 4A to 4C) is provided on the insulating film14 in the substrate to be transferred 11A, a space G is formed betweenthe donor substrate 40C and the insulating layer 14. As illustrated inFIG. 8, the donor substrate 40C and the insulating layer 14 are not incontact with each other. Therefore, deterioration of image qualitycaused by a light emission line or the like is avoided while suppressinggeneration of steps in the deposited organic layer 15 due to the contactbetween the donor substrate 40C and the insulating layer 14.

Next, as illustrated in FIG. 19, a radiation ray R is irradiated fromthe rear surface side of the donor substrate 40C, and the transfer layer50 is sublimated or vaporized and thus transferred to the substrate tobe transferred 11A. Thereby, the red light emitting layer 15CR isformed. At that time, as illustrated in FIG. 20, a plane drawing may beperformed by using a xenon flash lamp as the radiation ray R.Alternatively, as illustrated in FIG. 21, a line drawing may beperformed by using a line beam RB in which a halogen lamp as theradiation ray R is condensed by optical system and moving the line beamRB in a direction of arrow A5.

Here, the heat interfering layer 46 includes the first interfering layer46A and the second interfering layer 46B having refraction indexdifferent from each other. Thereby, when the reflectance of the heatinterfering layer 46 is adjusted depending on the light emission band ofthe radiation ray R, the absorption when the radiation ray R irradiatedto the donor substrate 40C is absorbed in the photothermal conversionlayer 42 and converted into heat improves. Therefore, the radiation rayR with a wide wavelength is efficiently absorbed, and the loss issuppressed. Moreover, the power used for the transfer is highly reduced.

At this time, since the radiation ray R is efficiently absorbed in theheat interfering layer 46, the heat diffusion in the pollutionpreventing layer 45 is reduced, and the transfer with high accuracy ispossible although the pollution preventing layer 45 is not separatedwith the convex structure 44.

In this manner, in the third embodiment, since the heat interferinglayer 46 has the stacked structure with the first interfering layer 46Aand the second interfering layer 46B having refraction index differentfrom each other, the absorption of the radiation ray R with a widewavelength improves and the loss is suppressed, and the power used forthe transfer is highly reduced.

In the third embodiment, the case where the pollution preventing layer45 is continuously formed on the surface of the heat insulating layer 43without providing the convex structure 44 is described. However, asillustrated in FIG. 22, it is also possible that the convex structure 44is formed on the heat insulating layer 43, and a first portion 45A and asecond portion 45B in the pollution preventing layer 45 are separatedwith the convex structure 44.

EXAMPLES

Specific examples of the present invention will be described.

Example 1

A display was manufactured in the same manner as the first embodiment.First, a first electrode 13 of ITO, an insulating layer 14 of polyimidewith a thickness of 1 μm, a rib 14A of polyimide with a height of 5 μm,and a hole injecting layer and a hole transporting layer 15AB wereformed on a driving substrate 11 of glass, and thereby a substrate to betransferred 11A was formed. The hole injecting layer and the holetransporting layer 15AB was formed by evaporation method. The holeinjecting layer of m-MTDATA had a thickness of 25 nm, and the holetransporting layer of α-NPD had a thickness of 30 nm.

Next, a donor substrate 40 was manufactured (refer to FIG. 5). Aphotothermal conversion layer 42 of chrome (Cr) with a thickness of 200nm was formed on a base 41 of glass by sputtering method. Thephotothermal conversion layer 42 was shaped in 100 μm in width and in astripe shape by, for example, photolithography method. Next, a heatinsulating layer 43 of SiO₂ with a thickness of 300 μm was formed by CVDmethod. A convex structure 44 of the above-described material with athickness of 3 μm was formed. The convex structure 44 was shaped in astripe shape, and had a cross section of an inverse taped shape.

After that, the pollution preventing layer 45 of molybdenum (Mo) with athickness of 150 nm was formed.

A transfer layer 50 with a thickness of 25 nm was formed in the donorsubstrate 40 by evaporation method (refer to FIG. 7A).

Next, the donor substrate 40 was arranged on the substrate to betransferred 11A (refer to FIG. 7B). Between the donor substrate 40 andthe substrate to be transferred 11A, a space G with a height ofapproximately 2 μm was maintained. This height of 2 μm corresponds tothe difference between the height of the rib 14A as 5 μm and the heightof the convex structure 44 as 3 μm. At this time, a laser light LB witha wavelength of 800 nm was irradiated from the rear surface side of thedonor substrate 40, and the transfer layer 50 was transferred to thesubstrate to be transferred 11A (refer to FIG. 7B). A spot size of thelaser light LB was fixed to 100 μm×20 μm. The laser light LB scanned ina direction orthogonal to the longitudinal direction of the spot size(swath width 100 μm).

By repeating the above steps, a red light emitting layer 15C, a greenlight emitting layer 15G, and a blue light emitting layer 15B wereformed, and then an electron transporting layer and an electroninjecting layer 15DE, and a second electrode 16 were formed byevaporation method. The electron transporting layer was made of Alq₃ andhad a thickness of 20 nm. The electron injecting layer was made of LiF(evaporation rate of 0.01 nm/sec), and had a thickness of 0.3 nm. Thesecond electrode 16 was made of MgAg, and had a thickness of 10 nm.After that, a protective film 17 and an adhering layer 20 were formed,and a sealing substrate 30 was adhered. Thereby, the display wascompleted.

As Comparative example 1, as illustrated in FIG. 23A, a donor substrate840 in which a reflecting layer 846 of aluminum (Al) was provided allover between a photothermal conversion layer 842 and a heat insulatinglayer 843 was formed. By using the donor substrate 840, a display wasmanufactured in the same manner as Example 1. At that time, thereflecting layer 846 was made of aluminum (Al) and had a thickness of100 nm.

The light emission state of the display in Example 1 and Comparativeexample 1 was confirmed by visual observation. Color mixture to animmediately adjacent pixel was not confirmed in Example 1. However, thecolor mixture to an immediately adjacent pixel was confirmed inComparative example 1. In both of Example 1 and Comparative example 1, awidth of a transferred light emitting layer was investigated. Theresults were indicated in Table 1.

TABLE 1 Transfer width Presence or Color mixture after irradiationabsence of to immediately with width convex structure adjacent pixel of100 μm Example 1 Present Not observed 105 μm Comparative Absent Observed122 μm example 1

From Table 1, it was understood that when the laser light was irradiatedby setting a long side (swath width) of the spot size as 100 μm, thewidth of the transferred light emitting layer was 105 μm in Example 1,and 122 μm in Comparative example 1. The transfer accuracy highlyimproved in Example 1 in comparison with Comparative example 1.

The reason may be considered as follows. In the donor substrate 840 ofComparative example 1 illustrated in FIG. 23A, when the laser light LBwas irradiated to the whole surface, the laser light LB was reflected bythe reflecting layer 846 in the region where the photothermal conversionlayer 842 was not formed as indicated with arrow A2 in FIG. 23B. On theother hand, in the region where the photothermal conversion layer 842was formed, the laser light LB was absorbed in the photothermalconversion layer 842, and only a desired range 852 in the transfer layer850 was transferred to the substrate to be transferred. However, in thedonor substrate 840 of Comparative example 1, heat conduction wasgenerated in the reflecting layer 846 as indicated with arrow A3. Thus,organic material for the transfer layer 850 was melted and slack of theoutline occurs. Accordingly, not only the desired range 852 in thetransfer layer 850, but also an undesired range (region undesired to betransferred) 851 was transferred. Therefore, transfer accuracy wasreduced and color mixture to an immediately adjacent pixel occurred.

That is, when the pollution preventing layer 45 included the firstportion 45A formed on the top surface of the convex structure 44 and thesecond portion 45B formed on the top surface of the heat insulatinglayer 43, and the first portion 45A and the second portion 45B wereseparated from each other, the heat diffusion through the pollutionpreventing layer 45 was highly reduced, and the desired range in thetransfer layer 50 was transferred with high accuracy.

Examples 2 and 3

A display was manufactured in the same manner as the third embodiment.At that time, in Example 2, a xenon flash lamp was used as a radiationray R, and a transfer step was performed by a plane drawing asillustrated in FIG. 20. The configuration of a donor substrate 40C wasas follows.

Base 41: glass Heat interfering layer 46: stacked structure by stackinga first interfering layer 46A of SiO₂ with a thickness of 100 nm and asecond interfering layer 46B of a-Si with a thickness of 15 nmPhotothermal conversion titanium (Ti) with a thickness of 200 nm layer42: Heat insulating layer 43: SiO₂ with a thickness of 300 nm Pollutionpreventing layer 45: aluminum (Al) with a thickness of 50 nm

In Example 3, a line beam RB in which a halogen lamp was condensed withoptical system was used as a radiation ray R, and a transfer step wasperformed by a line drawing as illustrated in FIG. 21. The configurationof a donor substrate 40C was as follows.

Base 41: glass Heat interfering layer 46: stacked structure by stackinga first interfering layer 46A of SiO₂ with a thickness of 200 nm and asecond interfering layer 46B of a-Si with a thickness of 35 nmPhotothermal conversion titanium (Ti) with a thickness of 200 nm layer42: Heat insulating layer 43: SiO₂ with a thickness of 300 nm Pollutionpreventing layer 45: aluminum (Al) with a thickness of 50 nm

As Comparative examples 2 and 3, a display was manufactured in the samemanner as Examples 2 and 3 except that a first interfering layer was notprovided in a donor substrate (a single-layer structure of only a secondinterfering layer).

Irradiation power of the radiation ray R used in Examples 2 and 3 andComparative examples 2 and 3 was investigated. The results wereindicated in Table 2 and Table 3.

TABLE 2 Case of using flash lamp Presence or absence Necessary power offirst interfering layer density (J/cm²) Example 2 present 40 Comparativeabsent 320 example 2

TABLE 3 Case of using halogen lamp (2800 K) Presence or absenceNecessary power of first interfering layer density (w/cm²) Example 3present 400 Comparative absent 70 example 3

As understood from Table 2 and Table 3, in Examples 2 and 3 where theheat interfering layer 46 had the stacked structure by stacking thefirst interfering layer 46A and the second interfering layer 46B havingrefraction index different from each other, the irradiation power washighly reduced in comparison with Comparative examples 2 and 3 where thefirst interfering layer was not provided. That is, when the heatinterfering layer 46 had the stacked structure by stacking the firstinterfering layer 46A and the second interfering layer 46B havingrefraction index different from each other, power necessary for thetransfer was highly reduced.

Module and Application Examples

Hereafter, Application examples of a display described in the first tothird embodiments will be described. The display according to theembodiments is applicable to a display in electronic devices in variousfields such as a television, a digital camera, a notebook personalcomputer, a portable terminal of a cellular phone or the like, or avideo camera in which an image signal input from outside or an imagesignal generated inside the device is displayed as a picture or image.

Module

For example, as a module illustrated in FIG. 24, the display accordingto the embodiments is installed in various electronic devices ofApplication examples 1 to 5 and the like which will be described later.This module is, for example, provided with a region 210 exposed from asealing substrate 30 and an adhering layer 20 to one side of a drivingsubstrate 11. In the exposed region 210, a line of a signal line drivingcircuit 120 and a line of a scanning line driving circuit 130 areextended to form an external connecting terminal (not illustrated in thefigure). In the external connecting terminal, a flexible printed circuit(FPC) 220 for inputting/outputting a signal may be provided.

Application Example 1

FIG. 25 illustrates appearance of a television to which the displayaccording to the embodiments is applied. This television deviceincludes, for example, an image display screen 300 including a frontpanel 310 and a filter glass 320. The image display screen 300 isconfigured with the display according to the embodiments.

Application Example 2

FIGS. 26A and 26B illustrate appearance of a digital camera to which thedisplay according to the embodiments is applied. This digital cameraincludes, for example, a flash light emitting section 410, a display420, a menu switch 430, and a shutter button 440. The display 420 isconfigured with the display according to the embodiments.

Application Example 3

FIG. 27 illustrates appearance of a notebook personal computer to whichthe display according to the embodiments is applied. This notebookpersonal computer includes, for example, a body 510, a keyboard 520 forinput operation of letters and the like, and a display 530 displayingimage. The display 530 is configured with the display according to theembodiments.

Application Example 4

FIG. 28 illustrates appearance of a video camera to which the displayaccording to the embodiments is applied. This video camera includes, forexample, a body 610, a lens for imaging an object 620, a start/stopswitch for imaging 630, and a display 640. The display 640 is configuredwith the display according to the embodiments.

Application Example 5

FIGS. 29A to 29G illustrate appearance of a cellar phone to which thedisplay according to the embodiments is applied. In this cellar phone,for example, a top case 710 and a bottom case 720 are connected with aconnecting section (hinge) 730 in between. The cellar phone includes adisplay 740, a sub-display 750, a picture light 760, and a camera 770.The display 740 and the sub-display 750 are configured with the displayaccording to the embodiments.

Hereinbefore, the present invention is described with the embodimentsand the examples. However, the present invention is not limited to theabove embodiments and examples, and various modifications may be made.For example, in the embodiments and the examples, the case where aradiation ray such as the laser light or the flash lamp is irradiated inthe transfer step is described. However, irradiation may be performedwith a radiation ray of other light sources such as a heat bar and athermal head.

In the above embodiments, the case where all of the light emittinglayers 15C of R, G, and B are formed by transfer method is described.However, as illustrated in FIG. 30, after forming only the red lightemitting layer 15CR and the green light emitting layer 15CG by transfermethod, the blue light emitting layer 15CB may be deposited over thewhole surface by evaporation method. At this time, in the organic lightemitting device 10R, although the red light emitting layer 15CR and theblue light emitting layer 15CB are formed, energy transfer occurs to redwhich has the lowest energy level, and a red light emission becomesdominant. In the organic light emitting device 10G, although the greenlight emitting layer 15CG and the blue light emitting layer 15CB areformed, energy transfer occurs to green which has the lowest energylevel, and a green light emission becomes dominant. In the organic lightemitting device 10B, since only the blue light emitting layer 15CB isformed, a blue light emission is generated.

For example, the material and the thickness of each layer, thedeposition method, the deposition conditions, and the irradiationconditions of the laser light described in the above embodiments andexamples are not limited. Other material and thickness are possible.Other deposition methods, deposition conditions, and irradiationconditions are possible. For example, the first electrode 13 may includea dielectric multilayer film.

For example, although the case where the first electrode 13, the organiclayer 15, and the second electrode 16 are stacked in order from thedriving substrate 11 side on the driving substrate 11 and light is takenout from the sealing substrate 30 side is described in the embodiments,the stacking order may be in reverse order. In this case, it is possiblethat the second electrode 16, the organic layer 15, and the firstelectrode 13 are stacked in order from the driving substrate 11 side onthe driving substrate 11, and the light is taken out from the drivingsubstrate 11 side.

For example, although the case where the first electrode 13 is regardedas an anode and the second electrode 16 is regarded as a cathode isdescribed in the embodiments, it is possible that the anode and thecathode are switched. In this case, the first electrode 13 may beregarded as a cathode and the second electrode 16 may be regarded as ananode. Moreover, it is possible that the first electrode 13 is regardedas a cathode and the second electrode 16 is regarded as an anode and thesecond electrode 16, and the organic layer 15, and the first electrode13 are stacked in this order from the driving substrate 11 side on thedriving substrate 11. Then, the light is taken from the drivingsubstrate 11 side.

In the embodiments, although the layer configuration of the organiclight emitting devices 10R, 10G, and 10B is specifically described asabove, it is not always necessary to include all of the layers, andother layers may further be included. For example, between the firstelectrode layer 13 and the organic layer 15, a hole injecting thin filmlayer of chrome oxide (III) (Cr₂O₃), ITO (indium-tin oxide: oxide mixedfilm of indium (In) and tin (Sn)), or the like may be provided.

Although the case where the second electrode 16 is configured with asemi-transmitting electrode and light generated in the light emittinglayer 15C is taken out from the second electrode 16 side is described inthe embodiments, the generated light may be taken out from the firstelectrode 13 side. In this case, it is preferable that the secondelectrode 16 have reflectance as high as possible to improve the lightemission efficiency.

Moreover, although the case of the active matrix display is described inthe embodiments, the present invention is applicable to a passive matrixdisplay. The configuration of the pixel driving circuit for driving theactive matrix is not limited to the aspects described in the aboveembodiments, and a capacitor or a transistor may be added if necessary.In that case, in addition to the signal line driving circuit 120 and thescanning line driving circuit 130 described above, a necessary drivingcircuit may be added according to a change in the pixel driving circuit.

Although the present invention has been described with reference to theembodiments and modification, the invention is not limited to those, andvarious modifications may be made.

The present application contains subject matter related to thatdisclosed in Japanese Priority Patent Applications JP 2008-165971 filedon Jun. 25, 2008 and JP 2008-313105 filed on Dec. 9, 2008 in the JapanPatent Office, the entire content of which is hereby incorporated byreference.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

1. A donor substrate comprising: a base layer; a photothermal conversionlayer arranged on a portion of the base layer; at least two first heatinsulating layers over the base layer and the photothermal conversionlayer; and a transfer layer on the first heat insulating layers made ofa light emission material which is released by sublimation orvaporization from the donor substrate upon irradiation of the donorsubstrate with a laser light, wherein, each of the first heat insulatinglayers has a refraction index that is different than another of thefirst heat insulating layers.
 2. The donor substrate according to claim1, wherein the refraction indices and thicknesses of the two or morefirst heat insulating layers are such that reflectance in a continuouswavelength region of 100 nm or more in a light emission band in thelaser light is 0.1 or less.
 3. The donor substrate according to claim 2,wherein the first heat insulating layers include: a first heatinsulating layer made of SiO₂, SiN, SiON, or Al₂O₃ and having athickness of 50 nm or more and 250 nm or less; and a second first heatinsulating layer made of a-Si and having a thickness of 15 nm or moreand 80 nm or less, in order from the base side.
 4. The donor substrateaccording to claim 1 comprising: a second heat insulating layer betweenthe photothermal conversion layer and the base layer.
 5. The donorsubstrate according to claim 4, including a convex structure on thefirst heat insulating layers in a region not coincident with thephotothermal conversion layer, and a pollution preventing layer thatincludes a first portion formed on the convex structure and a secondportion formed on the first heat insulating layers, the first portionand the second portion being separated from each other.
 6. A donorsubstrate comprising: a base layer; a photothermal conversion layerarranged on a portion of the base layer, corresponding to a region wherea light emitting layer on a transfer substrate is to be formed; at leasttwo first heat insulating layers formed over the photothermal conversionlayer and the base layer; a transfer layer on the first heat insulatinglayers that is made of a light emission material which is released bysublimation or vaporization from the donor substrate upon irradiation ofthe donor substrate with a laser light a convex structure on the firstheat insulating layers in a region not coincident with the photothermalconversion layer; and a pollution preventing layer that includes a firstportion formed on the convex structure and a second portion formed onthe first heat insulating layers, the first portion and the secondportion being separated from each other.
 7. The donor substrateaccording to claim 6, wherein the convex structure has a cross sectionof an inverse tapered shape with a bottom width smaller than a topwidth.
 8. The donor substrate according to claim 6, wherein the convexstructure has a height of 0.3 μm or more and 10 μm or less.
 9. The donorsubstrate according to claim 6, wherein the pollution preventing layerhas a thickness of 25 nm or more and 500 nm or less.
 10. The donorsubstrate according to claim 6, wherein a second heat insulating layeris provided between the base layer and the photothermal conversionlayer.